Field of the Disclosure
The present disclosure generally relates to controlling lost circulation in a wellbore, such as during drilling with a drilling fluid. More specifically, embodiments of the disclosure relate to a lost circulation material (LCM).
Description of the Related Art
Lost circulation is one of the frequent challenges encountered during drilling operations. Lost circulation can be encountered during any stage of operations and occurs when drilling fluid (such as drilling mud) pumped into a well returns partially or does not fully return to the surface. While some fluid loss is expected, excessive fluid loss is not desirable from a safety, an economical, or an environmental point of view. Lost circulation is one of the major causes of non-productive time (NPT) and is associated with problems with well control, borehole instability, pipe sticking, unsuccessful production tests, and poor hydrocarbon production after well completion.
Lost circulation can occur in various formations, such as naturally fractured formations, cavernous formations, and high permeable formations. Lost circulation can be categorized by the amount of fluid or mud lost as seepage type, moderate type, severe type, and total loss. The extent of the fluid loss and the ability to control the lost circulation with an LCM depends on the type of formation in which the lost circulation occurs. For example, high permeable, super-K (for example, having an extremely high permeability of greater than 500 millidarcy), fractured, vugular, and cavernous formations may lost a large volume of drilling mud and experience a rapid drop of mud column in the wellbore. The rapid drop of mud column may lead to various drilling problems such as stuck pipe, wellbore instability, and kicks or blowouts that may result in side tracking or abandonment of a well.